Bar soap composition



Patented .Feb. 29, 1944 UNITED STATES m'rlazrrr OFFICE 2.842.786 '4 Ban soar 'courosmon Ferdinand nome nn and Hans Huber, m... baden-Biebrieh, Germany: vested in the Alien Property Gas No Drawing. Application June 26. 1940. Serial No. 342.564. In Germanyl 'ebruaryfi. 1935 2 Claims. ccl. 252-109) This invention relates to an improved bar soap composition and more particularly to such a composltion'consisting essentially of a sodium soap and a small proportion of an alkali metal polyphosphate.

The use of alkali metal pyro and meta-phosphates as anti-precipitating agents in hard water is, now well known. Furthermore, these materials have been suggested for use in combi- 4 nation with soap as soap-improvingingredients They in powdered and liquid soap mixtures. have not been satisfactory for use in solid bar soap because the pyrophosphates tend to crystallize and produce a soap of frosty appearance which is unsightly and unsalable. The metaphosphates are'not stable in the presence of the portion, preferably not less than 15%, of an al-' kali metal tripolyphosphate.

The preferred polyphosphate is sodium tripolyphosphate (NasPaom) It, is stable in moist bar soaps and does not produce an undesirable appearance on the passage of time. It greatly improves the emulsifying power of the soap in hard water, yields a rich creamy lather, and modifies the alkaline reaction of the soap so that it will not irritate the skin.

As an example of the soap composition, 100 kilograms of a solid laundry soap having a 75% fatty acid content was mixed with 6 kilograms of sodium tripolyphosphate and 14 kilograms of water. The mixture was then milled to a homogeneous mass, shaped, and permitted to set up into a-hard solid mass. After three years 85% of the phosphate was still in the form of the original tripolyphosphate.

Theamount ofsodium tripolyphosphate may be varied over a wide range, but in general it is preferred to employ from- 5% to 15% based upon the total weight of the soap bar. Amounts from 1% to 5%, however, are quite satisfactory for use in most types of water, and particularly the softer waters.

The foregoing detailed description has been given for clearness of understanding only, and

no unnecessary limitations should be understood therefrom for some modifications will be obvious to those skilled in the art.

What is claimed as new and desired to secure by letters Patent is:

1. A bar soap consisting essentially of a sodium soap of a fatty acid normally precipitable by calcium salts in water, and from one to fifteen per cent by weight of sodium tripolyphosphate rendering the soap non-precipitable by calcium salts in normally hard water, the soap containing suilicient water tomaintain the soap in bar form, the bar being stable against frosting.

2. A bar soap consisting essentially of a sodium soap,of a fatty acid, normally precipitable by calcium salts in water, and a small proportion of an alkali metal tripolyphosphate suflicient to render the soap non-precipitable by calcium salts in normally hard water, the amount being at least 1% by weight, the soap containing sufficient water to maintain the soap in bar form, the bar being stable against frosting.

1 FERDINAND. BORNEMANN. HANS HUBER. 

